1. Field of the Invention
The present invention relates to an imaging device and a power supply control method of the imaging device.
2. Description of the Related Art
A camera system is known in which a backup camera for taking photographs of the back side of an automobile is installed at a back part of the automobile so that the driver can check the back side of the automobile on a screen installed inside the vehicle. The images taken by the backup camera are displayed on a display of a car navigation device or displayed on a display installed at the position of the back mirror when the automobile is moving backward.
An example shown in FIG. 7 is a camera system 1 in which a camera 50 for taking photographs of the back side of the automobile is connected to a car navigation device 20. FIG. 7 is a block diagram showing a camera system 1 of the related art. The camera 50 includes a camera power supply circuit 54, a video signal processing circuit (DSP) 56, a CCD image sensor 58, a video driver 59, and the like. The car navigation device 20 includes a control unit 22, a display 24, and the like. In the camera system 1, a rear gear detection unit 12 detects the state of a gear 10 and outputs a rear gear ON signal, indicating whether or not the gear 10 is in a rear state, and the control unit 22 of the car navigation device 20 controls ON/OFF of the power of the camera 50 based on the rear gear ON signal. At the same time, the control unit 22 of the car navigation device 20 controls display or non-display of the display 24.
An example shown in FIG. 8 is a camera system 2 in which a vehicle is not mounted with the car navigation device and a camera 50 and a display 40 are connected. FIG. 8 is a block diagram showing a camera system 2 of the related art. In the camera system 2, the camera 50 is connected to a battery 30 and is conducted on a steady basis. The display or non-display of the display 40 is controlled when the display 40 detects the state of the gear of the vehicle based on the rear gear ON signal.
Japanese Patent Application Laid-Open No. 11-55656 discloses detecting a signal of a rear gear, a backup lamp, or the like, and having a display device switch the display of the video from a camera and another external video.
In Japanese Patent Application Laid-Open No. 7-236134 discloses a camera system 3 in which the camera 50 includes a power supply control unit 52 (=relay circuit), a camera power supply circuit 54, a video signal processing circuit 56, a CCD image sensor 58, and the like as shown in FIG. 9. FIG. 9 is a block diagram showing a camera system 3 of the related art. The camera power supply circuit 54 supplies driving power to the camera 50 by the input of the rear gear ON signal. The camera 50 and the display 40 are connected with a connection cable for transmitting video signals.